The invention relates to a device for regulating the temperature of the intake air in an internal combustion engine
Such devices, as have become known from German Patent 15 26 662, for example, are simple in construction and accordingly inexpensive to produce. The wax thermostat constitutes a regulating means with sufficient power and adequate stroke length for its intended purpose.
A disadvantage of this apparatus, however, is to be seen in the fact that all of the components are disposed in the duct for the cold air or mixed air, resulting in increased resistance to flow. An effort is therefore made to streamline the flow device and avoid the use of large parts.
German Offenlegungsschrift discloses a device which is contained in a shunt duct. Mixed air flows around this device, but here again the mixed air has to overcome considerable flow resistance.
U.S. Pat. No. 4,340,172 furthermore discloses a device for regulating the temperature of the intake air in an internal combustion engine. This one is also situated largely in the mixed air duct and from there it controls two flaps arranged parallel and operating contrariwise.
A disadvantage of this device is to be seen in the fact that the mixed air encounters considerable resistance to flow. Moreover, on the basis of the principle of its design, both a restoring spring is necessary for the wax thermostat as well as an overtravel compensation spring and a restoring spring for the control valve.
The restoring spring for the wax thermostat and the overtravel spring are concentric inside of one another. A disadvantage of this arrangement, however, is that here the diameter of the device is very greatly increased and therefore, again, the flow properties are very greatly affected.